In computing, a softphone is a software program for making telephone calls over the Internet using a general purpose computer, rather than using dedicated hardware. Often a softphone is designed to behave like a traditional telephone, sometimes appearing as an image of a phone, with a display panel and buttons with which the user can interact. A softphone is usually used with a headset connected to the sound card of the PC, laptop, or the like, or with a USB phone.
Traditionally, softphone applications have had embedded support only for voice and video communication. When a specialized communication medium is required, such as Teletypewriter or Teletype (TTY), the softphone must be operated in a mode that places it in conjunction with a separate special-purpose endpoint device. It may be possible to provide embedded support for TTY into a softphone. However, if TTY communications are required, then a text chat window will need to be populated on the softphone.